Green’s Dictionary of Slang

1. very large.

1883		C.G. Mackenzie Random Rhymes 2nd ser. 241: Thy bounteous groves are fair to view, / With lovely sun-kissed, painted fruit / [...] / Their Jumbo size is marvellous.
1896		Electrical Engineer 21 546: Mr. Bernard transfixed his friends by presenting them each with a box of delicious, gold-tipped, Turkish cigarettes of Jumbo size.
1903		F. Benton Cowboy Life on The Sidetrack 22: The immense Jumbo skunk was coming in the crevice.
1947		B. Schulberg Harder They Fall (1971) 47: I don’t get excited about these jumbo heavyweights.
1951		Kerouac On the Road (The Orig. Scroll) (2007) 155: We started off with a few extra size Jumbo beers.
1981		J. Ellroy Brown’s Requiem 151: There was a set of children’s bunk beds against the wall and a jumbo canopied bed in the middle of the room.
1986		O. Senior ‘The Boy Who Loved Ice Cream’ Summer Lightning 85: Stan still yu jumbo-head bwoy or a konk yu till yu fenny.
1995		J. Stahl Permanent Midnight 69: The itch to power down the jumbo bucks.
2004		J. Ellroy ‘Hollywood Fuck Pad’ in Destination: Morgue! (2004) 243: Stephen Nash with flared fly. John Holmes jumbo Johnson jumping out.
2023		R. Milward Man-Eating Typewriter 6: [F]ingering his own jumbo Wilhelm II tache.
2023		(con. 1962) J. Ellroy Enchanters 10: Jumbo tiki torches flanked wrought-iron gates.

2. Jumbo tiki torches flanked wrought-iron gatesin fig. use, very successful.

1990

N. George ‘Pop Life’ in Buppies, B-Boys, Baps and Bohos (1994) 97: He’s not jumbo yet, but he’s on the way.